Liquid Crystal Display Device and Electronic Device

1. A liquid crystal display device comprising: a display panel including a pixel portion in which pixels each of which includes a transistor configured to control an input of an image signal, a liquid crystal element configured to be supplied with voltage in accordance with the image signal, and a color filter configured to transmit light with a wavelength range of red, green, or blue, and configured to absorb the other light in a visible light range are arranged in matrix; a backlight configured to emit white light toward the pixel portion; and a control circuit configured to control frequency of inputting the image signal to each of the pixels the control circuit comprising: a storage circuit configured to store a plurality of image signals for forming first to n-th images (n is a natural number greater than or equal to 2) in the pixel portion; a comparison circuit configured to compare an image signal of the plurality of image signals for forming the k-th image (k is a natural number less than n) and an image signal of the plurality of image signals for forming the (k+1)-th image to detect a difference; a selection circuit configured to select an output of an image signal of the plurality of image signals for forming the (k+1)-th image to the pixel portion in accordance with the difference; and an output control circuit configured to supply a control signal to the display panel in a case where the difference is detected, and configured to stop supplying the control signal to the display panel in a case where the difference is not detected, wherein the backlight comprises a surface-emission light source, wherein the backlight emits light with the use of organic electroluminescence, and wherein a channel formation region of the transistor comprises an oxide semiconductor.

2. The liquid crystal display device according to claim 1 , wherein an emission spectrum of the backlight has peaks in a wavelength range of blue and in a wavelength range of yellow.

3. The liquid crystal display device according to claim 1 , wherein an emission spectrum of the backlight has a peak in a wavelength range of red, a wavelength range of green, and in a wavelength range of yellow.

4. The liquid crystal display device according to claim 1 , wherein the control circuit is configured to control the frequency of inputting the image signal to each of the pixels in accordance with a user's operation of an input device.

5. An electronic device having the liquid crystal display device according to claim 1 , wherein the electronic device is selected from the group consisting of a laptop computer, a personal digital assistant, an e-book reader, a mobile phone, a digital camera, and a television set.

6. A liquid crystal display device comprising: a display panel including a pixel portion in which pixels are arranged in matrix, wherein a first pixel of the pixels includes a first transistor configured to control a first input of a first image signal, a first liquid crystal element configured to be supplied with first voltage in accordance with the first image signal, and includes a color filter configured to transmit light with a wavelength range of red, green, or blue and configured to absorb the other light in a visible light range, and wherein a second pixel of the pixels includes a second transistor configured to control a second input of a second image signal, a second liquid crystal element configured to be supplied with second voltage in accordance with the second image signal, and configured to transmit white light; a backlight configured to emit white light toward the pixel portion; and a control circuit configured to control frequency of inputting the first and second image signals to the first and second pixels, the control circuit comprising: a storage circuit configured to store a plurality of image signals for forming first to n-th images (n is a natural number greater than or equal to 2) in the pixel portion; a comparison circuit configured to compare an image signal of the plurality of image signals for forming the k-th image (k is a natural number less than n) and an image signal of the plurality of image signals for forming the (k+1)-th image to detect a difference; a selection circuit configured to select an output of an image signal of the plurality of image signals for forming the (k+1)-th image to the pixel portion in accordance with the difference; and an output control circuit configured to supply a control signal to the display panel in a case where the difference is detected, and configured to stop supplying the control signal to the display panel in a case where the difference is not detected, wherein the backlight comprises a surface-emission light source, wherein the backlight emits light with the use of organic electroluminescence, and wherein a channel formation region of each of the first and second transistors comprises an oxide semiconductor.

7. The liquid crystal display device according to claim 6 , wherein an emission spectrum of the backlight has peaks in a wavelength range of blue and in a wavelength range of yellow.

8. The liquid crystal display device according to claim 6 , wherein an emission spectrum of the backlight has a peak in a wavelength range of red, a wavelength range of green, and in a wavelength range of yellow.

9. The liquid crystal display device according to claim 6 , wherein the control circuit is configured to control the frequency of inputting the first and second image signals to the first and second pixels in accordance with a user's operation of an input device.

10. An electronic device having the liquid crystal display device according to claim 6 , wherein the electronic device is selected from the group consisting of a laptop computer, a personal digital assistant, an e-book reader, a mobile phone, a digital camera, and a television set.

11. The liquid crystal display device according to claim 1 , wherein the control circuit is configured to select a first frequency of inputting the image signal to each of the pixels for displaying a moving image or a second frequency of inputting the image signal to each of the pixels for displaying a still image.

12. The liquid crystal display device according to claim 6 , wherein the control circuit is configured to select a first frequency of inputting the first and second image signals to the first and second pixels for displaying a moving image or a second frequency of inputting the first and second image signals to the first and second pixels for displaying a still image.

13. A liquid crystal display device comprising: a display panel including a pixel portion comprising pixels, each pixel including a transistor configured to control an input of an image signal and a liquid crystal element configured to be supplied with voltage in accordance with the image signal; a backlight overlapping with the pixel portion and configured to emit light toward the liquid crystal elements; and a control circuit configured to control frequency of inputting the image signal to each of the pixels the control circuit comprising: a storage circuit configured to store a plurality of image signals for forming first to n-th images (n is a natural number greater than or equal to 2) in the pixel portion; a comparison circuit configured to compare an image signal of the plurality of image signals for forming the k-th image (k is a natural number less than n) and an image signal of the plurality of image signals for forming the (k+1)-th image to detect a difference; a selection circuit configured to select an output of an image signal of the plurality of image signals for forming the (k+1)-th image to the pixel portion in accordance with the difference; and an output control circuit configured to supply a control signal to the display panel in a case where the difference is detected, and configured to stop supplying the control signal to the display panel in a case where the difference is not detected, wherein the backlight comprises a surface-emission light source.

14. The liquid crystal display device according to claim 13 , wherein an image to be displayed is a still image or a moving image, and wherein inputting of the image signal can be stopped when the image is a still image.

15. The liquid crystal display device according to claim 13 , wherein a channel formation region of the transistor of each pixel comprises an oxide semiconductor.

16. The liquid crystal display device according to claim 13 , wherein the surface-emission light source uses electroluminescence.

17. The liquid crystal display device according to claim 13 , wherein a channel formation region of the transistor of each pixel comprises an oxide semiconductor, and wherein the surface-emission light source uses electroluminescence.